.tops {
  background-image: url(./images/htbg.png);
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  min-width: 1000px;
  z-index: -10;
  zoom: 1;
  background-color: #fff;
  background-repeat: no-repeat;
  background-size: cover;
  -webkit-background-size: cover;
  -o-background-size: cover;
  background-position: center 0;
}

/* canvas */
.content canvas{
  margin: 5% auto;
  /* border: 2px solid black; */
  /* display: block; */
  position:absolute;
  left: 0;
  right:0;
}